STREPTOZOTOCIN-SENSITIVE PANCREAS ISLET CELLS EXPRESS HUNTINGTIN ASSOCIATED PROTEIN 1

Objective To investigate the localization of huntingtin-associated protein 1(HAP1) in the pancreas islet of the rat.Methods To replicate rat model of diabetes through selectively destroying B cells of pancreas islet by one peritoneal injection of large dose of streptozotocin;the immunreactivities of HAP1 and insulin in the pancreas islet were showed by ABC method of immunohistochemistry.Results In the pancreas of normal rat,it was found that HAP1 expressed selectively in the islets.HAP1-containing cells were arranged as short cords or groups,mainly located in the center of each pancreas islet,having similar distributive pattern to that of pancreas islet B cell.No HAP1-immunoreactive cell was detected in the exocrine portion of the pancreas.The HAP1-containing cells in the diabetic rats decreased in number as early as 3 days after injection of streptozotocin and further progressively decreased as the rats survived longer,only a few of cells with weak HAP1-immunoreactivity remaining in the islets 4 weeks after streptozotocin injection.It was also noted that the effect of streptozotocin on the expression of HAP1 was similar to that on the expression of insulin in the islet.ConclusionHAP1 also exists in the pancreas islet,mainly located in streptozotocin-sensitive B cells.